PARIS (Reuters) - Police have arrested a high school student suspected of posting his own translation of the latest Harry Potter book on the Internet weeks ahead of the official French release date, a newspaper reported on Wednesday.

The 16-year old from the Aix-en-Provence region in southern France was taken into custody after a translation of the book's first three chapters appeared on the Web just days after the English-language release in late July, Le Parisien reported.

"The anti-counterfeiting police discovered the affair and contacted Ms. Rowling's lawyer," said a spokeswoman for publisher Gallimard, which handles the French editions of the Harry Potter novels.

Police were not immediately available for comment.

The official French language version of "Harry Potter and the Deathly Hallows" is scheduled for release on October 26. The translator is still working on the text, the spokeswoman said.

The seventh chapter of the Harry Potter saga is the fastest selling book in history, publishers say, with some 11 million English-language copies sold in the first 24 hours.

Many French book stores are selling the English-language version ahead of the French language release.